<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>button</title>
    <script src="jquery/jquery-3.1.1.min.js"></script>
    <script type="text/javascript" src="js/button.js"></script>
</head>
<body>
    <button onclick="showText()">内容</button>
</body>
</html>